P1159: INFERIOR OUTCOME OF FRAIL AND UNFIT PATIENTS WITH DIFFUSE LARGE B-CELL LYMPHOMA TREATED WITH ATTENUATED R-CHOP
Authors: Diana Al-Sarayfi, Mirian Brink, Martine E. D. Chamuleau, Rolf Brouwer, Roos van Rijn, Djamila Issa, Wendy Deenik, Gerwin Huls, Rogier Mous, Joost S.P. Vermaat, Josee M. Zijlstra, Tom van Meerten, Marcel Nijland
Journal: HemaSphere (2023)

Topic: 19. Aggressive Non-Hodgkin lymphoma - Clinical Background: For frail and unfit patients with diffuse large B-cell lymphoma (DLBCL), an attenuated chemo-immunotherapy strategy of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-miniCHOP) was introduced into standard of care as from 2014 onward in the Netherlands. Although R-miniCHOP is tolerable for frail patients, overall survival (OS) is inferior as compared to R-CHOP. This might be due to more relapses, treatment-related toxicity or unrelated deaths. Aims: This retrospective population-based study assesses the efficacy in terms of survival outcomes of patients treated with R-miniCHOP as compared to patients treated with R-CHOP. Methods: DLBCL patients ≥65 years, diagnosed in 2014-2020, who received at least one cycle of R-CHOP or R-miniCHOP were identified in the Netherlands Cancer Registry (NCR), with survival follow-up through 2021. Patients who either de-escalated from R-CHOP to R-miniCHOP or escalated from R-miniCHOP to R-CHOP were excluded. Patients with R-CHOP and R-miniCHOP were propensity-score matched 1:1 (nearest neighbor) for age, sex, Ann Arbor stage, International Prognostic Index (IPI) score at baseline and number of cycles received. The endpoints were overall response rate (ORR; best response complete or partial remission), OS and progression-free survival (PFS). Best response was determined by physician assessment using the Lugano classification as of 2014 onward, and as such routinely collected by trained registrars of the NCR. OS was defined as the time between diagnosis and death from any cause. PFS was defined as the time between diagnosis and relapse or death from any cause. Multivariable analysis to calculate risk of mortality after adjustment for the covariables age, sex, serum LDH, WHO performance score, number of extranodal sites, Ann Arbor stage, IPI score, and prior malignant disease, was performed using Cox regression. Results: In total, 768 patients treated with R-miniCHOP and R-CHOP (384 patients in each arm) were included for comparison (median age; 81 years (range, 65-94 years), stage 3-4; 68%, IPI 3-5; 29%). The median number of cycles received was 6 in both arms. The median follow-up was 26 months (inter quartile range [IQR], 12-49 months). At most, a trend was observed in the ORR between patients treated with R-miniCHOP and R-CHOP (72% vs. 78%, respectively; p=0.08). The 2-year OS was inferior for patients treated with R-miniCHOP as compared to R-CHOP (59% vs. 72%, p<0.01) and the 2-year PFS estimates for patients treated with R-miniCHOP and R-CHOP were 56% and 69%, respectively (p<0.01). In multivariable analysis, patients treated with R-miniCHOP had higher risk of mortality as compared to patients treated with R-CHOP (HR 1.41; 95%CI, 1.12-1.77), and was negatively affected by male gender, age ≥75 years, elevated serum LDH, WHO performance score ≥3 and high IPI-score. Summary/Conclusion: Although R-miniCHOP is an effective treatment for the majority of frail and unfit patients, survival is inferior as compared to patients treated with R-CHOP. Keywords: Survival, Epidemiology, Diffuse large B cell lymphoma, Treatment